1. Field of Invention
The present invention relates to medical devices. More particularly, the invention relates to intravascular catheters incorporating a tubular braid.
2. Background
The use of intravascular catheters for treatment of the body is well known in the field of medicine. The need for a choice of catheter sizes and types has grown rapidly as the techniques for their use have been greatly improved and the types of medical uses have expanded quickly. One such catheter is a guide catheter which includes a tubular member having a lumen therethrough. Guide catheters are commonly used in diagnostic and treatment techniques related to vascular disease such as angioplasty. A guide catheter is inserted into the femoral artery and routed to a location near a treatment or diagnostic site through the aorta over the aortic arch to the ostium of a target vessel. The guide catheter provides a conduit so that fluid or another medical device can be delivered easily to the proximate location of treatment via the lumen of the guide catheter.
Prior art catheters often comprise a tubular member including a pair of congruent tubes, the inner one defining the lumen. Flexibility is an essential part of the catheter so that it may be successfully torqued, pushed and pulled on its way through the vascular passage to the desired site in the body. For control of the catheter and to prevent its kinking from excessive flexing a certain amount of rigidity is also required. The prior art catheters often meet this need for rigidity by adding a support member between the two tubes. This support member may comprise a braid of metal wire wrapped around the inner tube, and often imbedded within the outer tube.
One problem that has arisen is that as it becomes desirable to increase the diameter of the catheter lumen, it also becomes desirable to decrease the thickness of the walls of the tubes that form the catheter. However, it has been found that in thinner-walled catheters it is more difficult to prevent the kinking of the catheter.
In view of the above, it is apparent that there exists a need for an improved intravascular catheter.